One type of vehicle suspension system which is becoming increasingly popular is the MacPherson strut suspension system. The MacPherson strut is an integral coil spring-shock absorber assembly which provides a lightweight, compact component of a vehicle suspension system. The MacPherson strut suspension system is disclosed in more detail in U.S. Pat. No. 2,624,592 to E. S. MacPherson.
One of the problems associated with MacPherson strut assemblies is related to the replacement of a worn shock absorber unit. One solution to this problem is to manufacture the MacPherson strut assembly with a construction which permits the shock absorber to be readily removed and replaced with a new shock absorber. However, such a repair procedure can be relatively time consuming, since typically the entire strut assembly must be removed from the vehicle.
One solution to reducing the time associated with repairing a MacPherson strut assembly is disclosed in U.S. Pat. No. 4,034,960 to K. D. Kloster. The Kloster patent discloses a pneumatically operated spring compressor which can be utilized to repair a strut assembly while the lower portion of the assembly remains attached to the vehicle. However, the economics of such a compressor can typically only be justified by repair shops which frequently repair strut suspension systems.
Smaller repair shops typically utilize a mechanically-actuated spring compressors of the type manufactured by Warren, Inc. of Jonesborough, Ark. This type of spring compressor includes a pair of spaced apart U-shaped hooks which are maintained in a facing relationship by means of an elongate bolt. In operation, typically two or three of the compressor units are circumferentially spaced about the coil springs and the bolts are alternately tightened to move the U-shape hooks toward one another, thereby compressing the spring.
Another type of mechanically actuated spring compressor is disclosed in U.S. Pat. No. 4,219,918 to Klann. The Klann patent discloses a spring compressor having a hollow guide tube and a threaded spindle rotatably mounted in the guide tube. A first spring engaging shoe is secured to one end of the guide tube, while a second spring engaging shoe is mounted on a sleeve which is slidable along the guide tube. The sleeve threadably engages the spindle such that rotation of the spindle causes movement of the second spring shoe along the guide tube.